n | a(n) |
---|---|
1 | 0 |
2 | 2 |
3 | 6 |
4 | 28 |
5 | 180 |
6 | 662 |
7 | 7266 |
8 | 24568 |
9 | 408360 |
10 | 1326122 |
11 | 30974526 |
12 | 98329108 |
13 | 3065784540 |
14 | 9596075582 |
15 | 384653685786 |
16 | 1192744081648 |
17 | 59724464976720 |
18 | 183983154281042 |
19 | 11249503075325046 |
20 | 34489251602450188 |
[0,2,6,28,180,662,7266,24568,408360,1326122, 30974526,98329108,3065784540,9596075582, 384653685786,1192744081648,59724464976720, 183983154281042,11249503075325046, 34489251602450188] |